IFNG and neoplasm: Based on activation mechanisms, macrophages are classified as M1 (activated by IFN-γ and TLR ligands, expressing higher levels of IL-12, IL-23, MHC II and inducible nitric oxide synthase, with tumoricidal effects) or M2 (activated by IL-4 and IL-13, expressing higher levels of IL-10 and TGF-β, and promote tumor progression) (28, 29).